The present invention relates to the method to prevent an abrasion on a silver halide photographic light-sensitive material and more particularly to the method for preventing the abrasion marks (desensitization) generated by the contact of the silver halide photographic light-sensitive material with a packing machine, a camera, a processing machine and the like.
A silver halide photographic light-sensitive material holds at least one light-sensitive silver halide emulsion layer on its support made of the material such as paper, glass, cellulose acetate film, polyester film or the like and the surface layer or the outermost layer thereof is normally a non-light-sensitive surface protective layer arranged on the emulsion layer though it sometimes is a light-sensitive silver halide emulsion layer. Such emulsion layer, the surface layer like a protective layer or the outermost layer contain a hydrophilic colloid such as gelatin or the like as a binder.
Such a silver halide photographic light-sensitive material containing gelatin as a binder has a high coefficient of friction against the surface of other metal or the surface of gelatin or the like and its surface is extremely subject to an abrasion caused by the contact, friction or the like. In the silver halide photographic light-sensitive material, in particular, an abrasion especially causes pressure marks, a pressure-desensitization or the like and thus detrimentally affects the photographic image because silver halide to be used as a light-sensitive substance reacts sharply even against the pressure.
Recently, the speed of manufacturing processes such as coating, drying and treatment for the silver halide photographic light-sensitive material has been increased compared with that in the past, the product forms have been diversified, packing machines in the treatment process have been complicated and further in the camera, the compactness thereof and automatic winding and rewinding or the like have been realized and various purposes for application have emerged. Thus the silver halide photographic light-sensitive material is in the tendency wherein it is generally used under the severe condition. Under such circumstances, therefore, the abrasion-resisting qualities and the prevention of the pressure marks (desensitization) of the silver halide light-sensitive emulsion caused by the abrasion are becoming increasingly important.
In a silver halide photographic light-sensitive material, a non-light-sensitive protective layer is usually arranged outside of a light-sensitive emulsion layer and further fine particles of an inorganic material such as silica, titanium dioxide, magnesium oxide or the like or an organic material such as polymethylmethacrylate, cellulose acetate propionate, polystyrene or the like are contained therein for the purpose of matting of the surface thereof and thus the contact area thereof is reduced and thereby the coefficient of friction thereof is controlled and the occurrence of the fog caused by the pressure is prevented. However, these methods tend to cause disadvantages such as impairing the transparency of the light-sensitive material and hurting the sharpness and graininess of images and thereby the amount of usage is naturally limited, which results in a less effect.
There are methods such as the one described in U.S. Pat. No. 3,042,522 wherein dimethylsilicone and a specific surface active agent are contained concurrently in the external layer and thereby a sliding property is given to the light-sensitive material or the one described in U.S. Pat. No. 3,121,060 wherein a high boiling solvent and solid paraffin are added to the external layer after there are dispersed in a gelatin aqueous solution. These methods are attended with undesirable side effects such as the increase in the so-called adhesion property that means an adhesion of films under the conditions of high temperature and high humidity, creating of coating troubles in the manufacturing process of silver halide photographic light-sensitive materials, deterioration of photographic characteristics and the trouble that substances added dissolve in the developer and settle.
Furthermore, in Japanese Patent Publication Open to Public Inspection Nos. 13923/1978, 85421/1978, there are described the methods for causing a silver halide light-sensitive emulsion layer contain a high boiling organic solvent against the pressure marks caused by the external physical pressure such as bending or strong squeezing of silver halide photographic light-sensitive material. In this method, however, a high boiling organic solvent moves to the external layer of the light-sensitive material in its storage under high temperature and high humidity because it has no miscibility with a hydrophilic binder and it has a great influence on the original photographic characteristic of the silver halide light-sensitive emulsion though it is used for the improvement of a physical property.
In the improvement of physical properties of a silver halide photographic light-sensitive material, as stated above, technologies presented in succession create successively the new disadvantages and a vicious cycle seems to be endless due to the complicated latent factors. Therefore, the primary object of the present invention is to provide a silver halide photographic light-sensitive material that is excellent in its abrasion-resisting qualities without impairing the photographic characteristic, transparency and adhesion property. The second object of the present invention is to provide a method for preventing the pressure marks (desensitization) of the silver halide light-sensitive emulsion layer caused by the abrasion without impairing the photographic characteristic, transparency and adhesion property.